Valve mechanism for controlling the discharge of powdered material and sand from tanks or other receptacles



April 3, 1928.

- L.A VALVE MECHANISM FOR CONTROLLING THE 1,665,081 NDREWS DISCHARGE OF POWDERED MATERIAL AND SAND FROM TANKS OR/OTHER REGEPTACLES Filed July 25, .1927 2 Sheets-Sheet l April 3, 1928. 1,665,081

L- ANDREWS VALVE MECHANISM FOR CONTROLLING THE DISCHARGE OF POWDERED MATERIAL AND SAND FROM TANKS OR OTHER RECEPTACLES Filed July 23, 1927 2 Sheets-Sheet .2

Patented Apr. 3, 1928.

UNITED ST TES A 1,665,081 AT NT v FI E- LEONARD ANDREWS, or WESTMINSTER, ENGLAND.

VALVE MECHANISM FOR CONTROLLING THE DISCHARGE F POWDERED AND SAND FROM TANKS OR OTHER RECEPTACLES.

MATERIAL Application filed July 23, 192?,Stria1 No. 207,978, and in Great Britain July 30, 1926.

This invention has reference to that kind of valve mechanism for automatically controlling the discharge of powdered material or sand from a tank or other receptacle (hereinafter referred to as a tank) wherein the action of said mechanism is dependent upon and accumulation of such material in the lower portion of the tank. The invention has for its object to provide valve mechanism of the kind referred to, that shall be of a robust, powerful and compact construction and be very sensitive in action.

For this purpose, valve mechanism according to the invention, comprises a loaded valve adapted to close the discharge outlet of the tank, a rotary device mounted to rotate in the lower portion of the tank and to be retarded to a greater or less extent by powdered material or sand collected therein,

a motor driven cam'device and adjustable means arranged to drive the said rotary device and to be acted upon by the loaded valve and by the cam device, the arrangement beingsuch that when the mechanism is in use and little or no solid material has collected in the lower portion ofthe tank, the valve will be held by its load in the closed position but when material collects in the lower portion of the tank, the resistance offered thereby to movement of the rotary device and of the adjustablemeans, causes the cam means to move the adjustable means in a direction to open the valve, against the action of its load, to a' greater or less extent,

depending upon the amount of material col lected in the lower portion of the tank.

The cam device may comprise part circular rotary cams having inclined faces, and

the adjustable means comprise rollers arranged to bear against the cam faces and to act against the loaded valve through a lever.

Also, the cam device and adjustable means may be arranged within a case supported at the top of the tank and the adjustable means be arranged in driving connection with the rotary device in the tank througha vertical shaft, the adjustable means being free to lift independently of the shaft.

Valve actuating mechanism embodying the invention can be variously constructed and arranged.

In the accompanying illustrative drawings, Fig. 1 shows in vertical section, one construction of valve mechanism according to the invention applied to a tank, from the bottom of which material is to be discharged in an automatic manner. Fig. 2 shows partly in side elevation and partly in vertical sectlon, valve mechanism according to the invent on, applied to apparatus for use in the class fication of powdered material by elutriation. Fig. 3 shows partly in elevation and partly in vertical section and Fig. at in plan, with parts removed, the valve actuatmg and controlling mechanism used with the loaded valve in the dewatering arrangement shown in Fig. 2.

In the construction shownin Fig. 1, a is a gear box mounted upon the top of a tube 5 through which liquid containing powdered material is delivered intoa tank 0 the lower portion 0 of which, of bowl shape, serves as a receptacle for solid material A precipitated from the liquid. Such receptacle has a contracted outlet 0 adapted to be closed by a valve (Z pivoted at e and provided with an arm f connected to a load, shown as a weight 9, that tends to close the valve. The mechanism for operating and controlling the valve, 7 comprises a pair of semi-circular shaped cams h and 2' having upwardly inclined faces arranged to be rotated at a very slow speed, as by bevel gear 70 from a shaft m driven from any convenient source, and a vertical centrally arranged rotary spindle n (hereinafter called the floating spindle) which acts against a lever 0 that is connected to the loaded valve (Z through a flexible or rigid tension member 7. The floating spindle a is provided with a pair of lateral arms a and a carrying rollers 10 and o which bear on the respective faces of the came. The degree of slope of the cam faces is not constant but increases from bottom to top. The floating spindle a is provided with a second pair of co-axial arms to which engage in oppositely arranged vertical slots a; in an enlarged end 1 of a vertical spindle 1 that extends centrally through the tank 0 into the collecting chamber c and is there connected by a pair of arms 2 to two quadrant shaped blades 3 arranged 7 within the collecting chamber, where. they become more or less embedded in the mass of coarse particles A collected therein; The arrangement is such that the floating spindle a is constantly subjected to two opposing stresses, namely, a downward pressure caused by the lever arm 0, due to the weight g acting to close the valve (Z and acting to cause the rollers u and o to run vdown the faces of the cams h and a and thus permit the valve to be closed, and to a retarding torque, due to motion of the blades 3 the mass of coarse particles A and whichtends to cause the R llers to roll up the faces of the said cams and thereby raise the floating spindle 71- and lever 0 and open the valve (Z to a greater or less extent. The arrangement is such that, at starting, when there are no oversize particles in the collecting chamber .c%, the valve d is held in its closed position by the :sveight g, and .the cams h and i. rollers a and o, floating spindle a, vertical spindle l and blades 3 rotate slowly as a whole. hen oversize particles have collected in the chamber 0 v and oiler a certain degree of resistance to motion of the blades the rollers {a and (v are caused to move a short distance up the faces of the cams h and v1 and thereby ,open the valve (Z to a small extent which allows coarse particles to escape, and it coarse particles are deposited i the chamber 0 at the same rate as coarseparticles are being discharged through the outlet 0 the valveWill remain practically stationary, and allow coarse particles to be discharged continuously at a constant rate. If coarse particles are deposited in the chamber a faster than they are being discharged, the mass of particles will increase and otter a greater resistance to motion of the blades 3 and thereby cause the said rollers u and '0 to travel to a higher position on the faces of the cams h and 2' and thereby cause the valve (Z to open to a greater extent. and permit of a greater discharge of particles to take place. If the coarse particlesyare being discharged at a greater rate than they are being deposited, the mass of particles will offer less resistance to the motion of the blades, and

the said rollers will descend the faces of the cams and permit the valve to move and reduce the rate of discharge oi: particles. It

' the rate of deposit of coarse particles falls to suchan extent that the mass thereof otters little or no resistance to movement of the blades, the saidrollers will fall sufficiently to enable the valve rl to close the discharge outlet 0? and the valve will not be again opened until asufficient mass of particles has formed to offer sufficient resistance to motion of the blades as to cause the rollers 20 and o to travel up the faces of the cams la and i and thereby again open the valve to a greater or less extent to enable the discharge of particles to again take place. Thus, the

discharge of coarse particles from the tank 0 is caused to. take place continuously or intermittently, in an automatic manner, according to the rate of deposit of coarse particles in the lower. portion of the tank.

Fig. 2 shows valve mechanism according to the invention applied in connection with the discharge valve at the bottom of apparatus of the kind described the specifica tion of another application for Letters Patent of even date herewith and numbered 14 548, according to Which the tank a is provided at the top with a vertical inlet tube 4.- through ;which a mixture of water with powdered material to be classified, is projected downward towards a horizontal partition 5 formed with a nnxnberot inverted conical passages 6 through which coarse particles of the powdered mixture separated from the water can fall into the bottom portion c of the tank 0 and be discharged through the outlet 0' under the control of the valve d in the manner hereinbetore described, Whilst a stream of clean water,

called teetering water, is admitted {by a pipe 7 below the partition 5, called a teetering partition, so as to flow upward through the passages Gtherein and remove fine particles from the coarse particles in the said passages and carry them into the; water above the partition where they are carri d with other line particles in the water flowing from the upper portion ,of the tank througha-n 1 outlet passage8 to the top of thetanl; and through an overflow trough 9 to an outlet pipe 10, as fully described in the "said other specification.

Figs- 3 an a S w a m fied arrang t au mati al y en e ag the ut let valve. plied to th las i yin apparatus s own in In is xamp h c ms h and \i are fixed to a worm wheel 11 driven by a W m 12 a a dri ng shaft an jour- Imlled 111 he upp e def a centr l a port a carried by the bottom plate (eer gear bo a his g ar es is as be the top o th t nk c as he arra gemen own n iglhe P r o r ll r a and a ar r e by a h rizontal shaft o the n -m po tion o w ich is fired a ve tica p d 15 x ending re ly inte a hole 16 in the shaft 1 to the lower'end of which the des (Fi s 1 an 2) a efi'xed T the per en o t sa d beit 'fixe a z nta P a e prbrted by ball b arns 18 m p q i d w th a'p'air ofvie ica guid a 1 9 o V S t on t a engage, i h the V shaped grooved peripheriesfofa pair of Wheels 20 m nte o tu n on th shaf 1 s a l ve p ot a one en a of d o e ed a it t e nd hrensh rod 7' to theweighted end of an outlet'valve d iske: t e le er in F s- 1- A1 intermediate portion of the. said "lever has jointed thereto at 0 an abutment device 21 that bears through a ball bearing 22 upon This arrangemengis shown. ap-

lie

tical ha t I s r ven. f m he ro at a s hand thro gh h se e s nd a sh ft. g ooved eels uide ba 1 an P at whole rr tating as o e p ec when there are no coarse particles in the collecting chamber 0 in which the blades 3 connected to the shaft 1 rotate. When the motion of the blades is retarded owing to accumulation of coarse particles in the said chamber, as hereinbefore described, the cams 71, and i move faster than the rollers at and 4) bearing thereon and lift the latter and the shaft 14, which, through the abutment device 21, lifts the lever 0 on its pivot 0 and opens the discharge valve d to a greater or less degree, as in the arrangement shown in Fig. 1.

In the example shown in Figs. 2, 3 and 4;, the pipe 7 used for supplying teetering water to the collecting chamber 0 below the teetering partition 5 2), is arranged to surround its shaft I and extend, like such shaft, through the teetering partition into the collecting chamber 0 It receives its supply of water from a chamber 3 formed in the central support 1 and connected to a supply pipe 25 A liquid tight packing 25 is arranged between the support 1 and shaft 1 at the top of the chamber 23.

The details of construction can be modified in various ways.

5. hat I claim is 2+ 1. For automatically controlling the discharge of powdered material from the outlet at the lower portion of a tank, mechanism comprisin a loaded valve adapted to close the discharge outlet of the tank, a rotary device arranged to rotate in the lower portion of the tank and to be retarded to a greater or less extent by solid material therein, a motor driven cam device and adjustable means arranged to drive the rotary device and to be acted upon by the loaded valve and by the cam device, the arrangement being such that when the mechanism is in use and little or no solid material has collected in the lower portion of the tank, the valve is held by its load in its closed position but when material collects in the lower portion of the tank, the resistance offered thereby to movement of the rotary device and of the adjusting means, causes the cam device to move the adjusting means in a direction to open the valve, against the action of its load, to a greater or less extent and' depending upon the amount of solid material collected in the lower portion of the tank.

2. Apparatus according to the preceding claim, wherein the cam device comprises part circular rotary cams having inclined surfaces and the adjustable means comprises rollers arranged to bear against the cam faces and to act against the loaded valve through a lever.

3. Mechanism according to claim 1, where in the cam device and adjustable means are arranged within a case supported at the top of the tank from which solid material is to be automatically discharged and the adjustable means are in driving connection with the rotary device in the lower end of the tank through a vertical shaft, the adjustable means being free to lift independently of the shaft.

Signed at London, England, this 14th day of July, 1927.

LEONARD ANDREWS. 

